I was trying to argue with a Sox fan yesterday (first problem) that in ranking the city's starters, Arrieta should be higher than Quintana, and in trying to argue that I found out that Arrieta's FIP (2.26) was second in all of baseball (min 150 innings) behind only Kershaw. Even xFIP (2.73) has him 5th in baseball, tied with Grienke and trailing only Kershaw, Felix Hernandez, Strasburg and Kluber. Not much to add, I just didn't realize he was even that much better than his ERA, which the Sox fan was arguing was a fluke and unsustainable. I might even have an argument that Arrieta should be 3rd ahead of Shark, behind Lester and Sale. Edit: The top 5 starters in the city by FIP 1. Arrieta 2.26 2. Sale 2.57 3. Lester 2.80 4. Quintana 2.81 5. Samardzija 3.20 By xFIP 1. Arrieta 2.73 2. Sale 2.83 3. Samardzija 3.07 4. Lester 3.10 5. Quintana 3.37